Is there any way to darken porcelain Veneers?

I made the stupid decision to get the absolute whitest shade of Veneers possible. Now my teeth look like absurdly white/opaque dentures. I read that Veneers are stain resistant, not stain proof. So if I drink a lot of coffee, can I stain them darker? I am so desperate that I am even willing to lightly sandpaper them so that they are more prone to staining. What can I do apart from replace them?